Surgical Stapling Instrument

ABSTRACT

A surgical stapling instrument ( 1 ) comprises a staple fastening assembly ( 2 ) including a curved cartridge device ( 10 ) and a curved anvil ( 12 ). The cartridge device ( 10 ) comprises at least one curved open row of staples which are formed by a staple forming face of the anvil ( 12 ). The anvil ( 12 ) can be moved relatively with respect to the cartridge device ( 10 ). A handle ( 4 ) in the proximal end region of the instrument is operatively connected to the staple fastening assembly ( 2 ). A flexible backbone, preferably an endoscope ( 6 ), is arranged between the handle ( 4 ) and the staple fastening assembly ( 2 ) and guides force transmitters ( 8, 9 ) of the moving device and the staple driving device.

REFERENCE TO RELATED APPLICATIONS

This continuation application claims the benefit of U.S. patentapplication Ser. No. 11/662,105 entitled: “Surgical StaplingInstrument”, filed on Jul. 9, 2007. Which is a 371 of PCT/EP2004/010138,filed on Oct. 9, 2004.

The invention relates to a surgical stapling instrument, which can beused, e.g., in the diagnosis and/or therapy of pathologies of the lowergastrointestinal tract.

Such a surgical stapling instrument is known from WO 01/91646 A1. WO01/91646 A1 discloses a surgical stapling instrument having a staplefastening assembly located in the distal end region of the staplinginstrument, a rigid shaft, and a handle extending from the shaft in theproximal end region of the stapling instrument. The staple fasteningassembly includes a curved cartridge device, which comprises severalcurved open rows of staples having a concave side and a convex side. Acurved anvil is arranged opposite to the cartridge device. The anvil hasa staple forming face and is adapted to cooperate with the cartridgedevice for forming the ends of the staples exiting from the cartridgedevice. The anvil can be moved relatively with respect to the cartridgedevice from a spaced position for positioning tissue therebetween to aclosed position for clamping the tissue. Moreover, a knife is containedin the cartridge device and is positioned on the concave side of atleast one row of staples and optionally the convex side of at least onerow of staples.

The surgical stapling instrument disclosed in WO 01/91646 A1 can be usedto excise tissue, e.g. polyps, and to stop bleeding virtuallyimmediately. In a surgical procedure, the stapling instrument isintroduced, e.g., into the anal canal and moved to the site of thetissue to be resected. The tissue to be excised can be pulled into thearea between the anvil and the cartridge device, when the cartridgedevice and the anvil are in a spaced or open position, by means of aseparate tissue grasping instrument. Afterwards, the anvil is movedrelatively with respect to the cartridge device in order to clamp thetissue. When the cartridge device and the anvil have reached the closedposition, the surgeon can “fire” the instrument, which means that thestaples are driven out of the cartridge device, penetrate the tissue,whereupon the ends are bent by the anvil, and the knife is moved towardsthe anvil in order to cut the tissue. When the instrument is opened, thecompletely excised tissue can be safely removed from the patient's bodytogether with or prior to removing the instrument itself

A particular advantage of the surgical stapling instrument disclosed inWO 01/91646 A1 is the shape of the staple fastening assembly in whichthe cartridge device and the anvil have a generally arc-like shape in across-sectional plane. This allows for unobstructed view and accesstowards the concave inner faces of the cartridge device and of theanvil.

When introduced, e.g., into the anal canal, the operational range of theinstrument known from WO 01/91646 A1 is restricted, however, and itcannot be used to excise tissue more remote from the rectum because ofits limited shaft length.

It is the object of the invention to provide a surgical staplinginstrument which has at least two major benefits, i.e. a largeroperational range than the stapling instrument disclosed in WO 01/91646A1 and the ability of being used by gastroenterologists (e.g. GI) in acolonoscopy setting thanks to the possibility to provide the staplinginstrument in a size noticeable smaller than the one disclosed in thestapling instrument of WO 01/91646 A1.

This problem is solved by a surgical stapling instrument having thefeatures of claim 1. Advantageous versions of the invention follow fromthe dependent claims.

The surgical stapling instrument according to the invention comprises,in the distal end region of the instrument, a staple fastening assemblyincluding a curved cartridge device and, opposite to the cartridgedevice, a curved anvil. The cartridge device comprises at least onecurved open row of staples having a concave side and a convex side. Theanvil has a staple forming face and is adapted to cooperate with thecartridge device for forming the ends of the staples exiting from thecartridge device. Moreover, a moving device is adapted to move the anvilrelatively with respect to the cartridge device, essentially in parallelrelationship, from a spaced position for positioning tissue therebetweento a closed position for clamping the tissue. A staple driving device isadapted to drive the staples out of the cartridge device towards theanvil. In the proximal end region of the instrument, a handle isoperatively connected to the staple fastening assembly and comprisesactuating members coupled to force transmitters of the moving device andof the staple driving device.

Optionally, the stapling instrument includes a knife, which is containedin the cartridge device and which is positioned on the concave side ofat least one row of staples and possibly the convex side of at least onerow of staples. The knife can be moved towards the anvil by means of aknife actuating device, which is preferably coupled to the stapledriving device, e.g. such that, upon actuation of the actuating memberof the staple driving device, the staples and the knife advancesimultaneously, the knife following the staples such that the tissue iscut after having been stapled.

According to the invention, a flexible backbone is arranged between thehandle and the staple fastening assembly. The flexible backbone is akind of flexible shaft or flexible connection between the handle and thestaple fastening assembly and guides the force transmitters of themoving device and of the staple driving device. The flexible backbonecan be rather long. It enables the stapling instrument to be introduced,e.g., into the anal canal and to be moved forward for a rather longdistance to allow for the treatment of tissue at a site remote from theanus. Upon advancement of the stapling instrument, the flexible backboneadapts to the curvature of the intestine.

In a preferred version of the invention, the flexible backbone comprisesa flexible endoscope, which preferably is removably mounted (i.e. it canbe detached from the rest of the instrument). The endoscope usuallyincludes observational optics and a light source and optionallycomprises a working channel in its longitudinal direction. The workingchannel can be utilized to place surgical tools at the site of surgery,e.g. an endoscopic gripping instrument for pulling tissue into the spacebetween the cartridge device and the anvil. The application of aflexible endoscope in the backbone of the stapling instrument has theadvantage that a standard component is used which can provideflexibility as well as strength to the stapling instrument.

The stapling instrument can be adapted to be used with an independentflexible endoscope forming at least part of the flexible backbone. Thatmeans, the stapling instrument according to the invention is distributedwithout the endoscope, and in order to put it into an operational state,the independently or separately distributed endoscope is connected tothe other parts of the instrument. Alternatively, the flexible endoscopeis a component or even an integral component of the stapling instrument.These options allow for a large design versatility and costeffectiveness.

In an advantageous version of the invention, the force transmitters ofthe moving device and of the staple driving device are located at theoutside of the endoscope and are attached to the endoscope by aplurality of spaced holders. If the knife actuating device has anindependent actuating member at the handle, a force transmitter of theknife actuating device can be arranged at the outside of the endoscopeas well. This design uses the endoscope as the only structuralconnection between the handle and the staple fastening assembly and isparticularly simple.

In another version, the flexible backbone comprises a flexible guide,which is arranged alongside the endoscope and which accommodates theforce transmitters of the moving device and of the staple drivingdevice. The guide, depending on its design, can connect the handle andthe staple fastening assembly in a structural sense.

In a preferred version of the invention, at least one of the forcetransmitters of the moving device and of the staple driving devicecomprises a flexible rotary rod adapted to be rotated around itslongitudinal axis upon actuation of the related actuating member of thehandle and adapted to transform its rotary motion to a longitudinalmotion at the staple fastening assembly. The term flexible rod is to beunderstood in a rather broad sense; it includes, e.g., a tightly woundhelix, which is flexible and can transmit torque, and even designscomprising linked members. When force is transmitted from the actuatingmember at the handle to the staple fastening assembly via a rotarymotion, the actual curved shape of the flexible backbone is not affectedby this rotary action in which the rotary rod rotates in some guide orsheath. In contrast thereto, a translational movement of forcetransmitters in a curved flexible shaft tends to straighten the shaft,which would be a great disadvantage in the use of such instrument.

Preferably, at least one of the force transmitters is adapted to berotated via a gear transmission operated by the related actuatingmember. Moreover, at least one of the force transmitters can be adaptedto transform its rotary motion to a longitudinal motion (required forthe relative movement of the anvil with respect to the cartridge deviceor for expelling the staples) via a screw drive.

The staple forming face of the anvil can be generally planar, but othershapes, e.g. an undulated shape, are conceivable as well.

In an advantageous version of the invention, the staple fasteningassembly is adapted to allow unobstructed access towards concave innerfaces of the cartridge device and of the anvil. Such design, which isgenerally known from WO 01/91646 A1, largely facilitates the handling ofthe stapling instrument in a surgical procedure.

Preferably, the cartridge device and the anvil have a generally arc-likeshape in a cross-sectional plane, the arc extending over an angle in therange 10° to 350°.

In a preferred version of the invention, the anvil is supported by meansof at least one arm extending from an end of the anvil and generallyrunning in parallel to the direction of relative movement of the anvilwith respect to the cartridge device. This arm can be driven by themoving device if the anvil is movable with respect to a fixed cartridgedevice. An optional second arm, preferably at the other end of theanvil, provides additional strength and facilitates an accuratealignment of the anvil with respect to the cartridge device, which isimportant for a precise alignment of the ends of the staples with thestaple forming face of the anvil. This kind of support allows for alarge unobstructed area between the cartridge device and the anvil.

Preferably, the distance between the cartridge device and the anvil inthe closed position is adjustable. For example, the moving device cancomprise an adjustable stop, e.g. at the related actuating member of thehandle, in order to prevent the cartridge device (or anvil) from movingbeyond the stop position and from clamping the tissue too much. Or aseries of cartridge devices with different built-in tissue stops can beused according to the tissue thickness. It is also conceivable to use aseries of cartridge devices which have different longitudinal dimensionswhich are adapted to the desired distance between the cartridge deviceand the anvil in the closed position. By adjusting the distance betweenthe cartridge device and the anvil in the closed position, theinstrument can be matched to the thickness and type of tissue to bestapled.

In an advantageous version of the surgical stapling instrument, thecartridge device comprises a replaceable cartridge containing thestaples. In this way, a used cartridge without staples can be replacedwith a fresh one, if required. This is particularly beneficial when theinstrument is to be used several times in the same patient.

Preferably, the staple fastening assembly and/or the handle areremovably mounted, relative to the flexible backbone, which allows foreasier handling and/or partial replacement of the stapling instrument.

Some of the features discussed above are already known from WO 01/91646A1, in particular an arc-like shape of the cartridge device and theanvil and a support arm extending from an end of the anvil, whichenables an easy access to the site of surgery, e.g., for endoscopicoptics or additional surgical instruments. Generally, the staplinginstrument according to the invention can be used in all kinds ofsurgery disclosed in WO 01/91646 A1, which is incorporated by referenceherein. A particular advantage of the invention, however, is the abilityto perform such surgery at locations more remote from an opening in thepatient's body and using GI techniques (e.g. non-surgical), such aslocal anesthesia or sedation.

Herein, the term “staple” is used in a very general sense. It includesmetal staples or clips, but also surgical fasteners made of syntheticmaterial and similar fasteners. Synthetic fasteners usually have acounterpart (retainer member) held at the anvil. In this sense, theterms “anvil” and “staple forming face” also have a broad meaning whichincludes, in the case of two-part synthetic fasteners, the anvil-liketool and its face where the retainer members are held, and similardevices.

In the following, the invention is described in more detail by means ofembodiments. The drawings show in

FIG. 1 an overall isometric view of a first embodiment of the surgicalstapling instrument according to the invention, including an endoscope,a staple fastening assembly in the distal end region and a handle in theproximal end region,

FIG. 2 an isometric view of the distal portion of the staplinginstrument of FIG. 1,

FIG. 3 an isometric view of one of several holders spaced along theendoscope,

FIG. 4 an isometric view of the internal mechanism of the handle,

FIG. 5 a side view of the internal mechanism of the handle,

FIG. 6 an isometric view of the distal end of the endoscope, the staplefastening assembly being removed,

FIG. 7 an isometric view of the components of the staple fasteningassembly driven by the mechanism in the handle, i.e. an arm supportingthe anvil and a pusher base used for expelling the staples,

FIG. 8 an isometric view similar to FIG. 7, with the staples and a knifeadded,

FIG. 9 an isometric view of some parts of FIG. 8 in a differentperspective,

FIG. 10 an isometric view of the staple forming face of the anvil andtwo guide rails used for guiding the knife,

FIG. 11 an isometric view of the fully assembled staple fasteningassembly with the anvil being in a spaced position,

FIG. 12 an isometric view of the staple fastening assembly, a housingbeing removed, with the anvil being in a closed position and the staplesjust fired,

FIG. 13 an isometric view of parts of FIG. 12 from a differentperspective,

FIG. 14 an isometric view similar to FIG. 12 with the housing beingattached and including the endoscope,

FIG. 15 an exploded view of the staple fastening assembly,

FIG. 16 an isometric overall view of a second embodiment of the surgicalstapling instrument according to the invention, including a flexibleguide and an endoscope, and

FIG. 17 an isometric view of the distal end region of the embodiment ofFIG. 16.

FIG. 1 is an isometric overall view of the surgical stapling instrument1 according to a first embodiment. The stapling instrument 1 comprises,in its distal end region, a stapling fastening assembly 2 and, in itsproximal end region, a handle 4. The handle 4 and the staple fasteningassembly 2 are connected via a flexible endoscope 6. In the embodiment,the endoscope 6 is a commercially available endoscope which is notmodified in order to be used in the stapling instrument. The endoscope 6serves as a flexible backbone and provides structural strength.

As shown in FIGS. 1 and 2, two force transmitters 8 and 9 running fromthe handle 4 to the staple fastening assembly 2 are guided by theendoscope 6. The force transmitters are used for transmitting forcesfrom the handle 4 to the staple fastening assembly 2 in order to performthe functions of the stapling instrument 1.

The main components of the staple fastening assembly 2 are a cartridgedevice 10, which contains several curved open rows of staples as well asa knife, and a curved anvil 12, which has a staple forming face and isadapted to cooperate with the cartridge device for forming the ends ofthe staples expelled from the cartridge device when stapling instrument1 is “fired”.

The anvil 12 can be moved with respect to the cartridge device 10 in aparallel relationship, i.e. in a direction parallel to the longitudinalaxis of the distal end portion of the endoscope 6. In the view of FIG.2, the anvil 12 has been entirely moved towards the cartridge device 10.

The mechanism and its components of the stapling instrument 1 used formoving anvil 12 relative to cartridge device 10 are generally calledmoving device, whereas the mechanism and the components used foradvancing the staples are generally called staple driving device.

FIG. 2 illustrates that the cartridge device 10 and the anvil 12 have agenerally arc-like shape. This design enables an easy access to theworking area between cartridge device 10 and anvil 12.

Moreover, FIG. 2 illustrates the arrangement of the distal portion ofthe endoscope 6 and the staple fastening assembly 2. The distal end faceof endoscope 6 has two openings, one for observational optics 14 and onefor a light source 15. Optionally, the endoscope can include a workingchannel which allows the introduction of a surgical instrument having aflexible shaft through the working channel of the endoscope to the siteof surgery, i.e. to the area of the staple fastening assembly 2.

In the embodiment, the force transmitters 8 and 9 are attached to theendoscope 6 by means of a plurality of spaced holders 16. FIG. 3 showsone of the holders 16 in enlarged view. Each holder 16 has a lock 17 andtwo recesses 18 and 19 for accommodating the force transmitters 8 and 9,respectively. For assemblage, the lock 17, which comprises adovetail-shaped protrusion and a notch fitting thereto, can be opened.The holder 16, which is manufactured from flexible material, allows theinsertion of the endoscope 6.

The mechanical connection between the endoscope 6 and the staplefastening assembly 2 or the handle 4 can be entirely accomplished bymeans of the holders 16 and the force transmitters 8, 9. In particularin the area of handle 4, the flexibility of this design, with no rigidattachment of the handle 4 to the endoscope 6, can be advantageous. Inthe distal end region of stapling instrument 1, the endoscope 6 may beadditionally fixed to the cartridge device 10 of the staple fasteningassembly 2, e.g. by bonding.

FIGS. 4 and 5 illustrate the internal mechanism of the handle 4. Handle4 comprises a grip 20 designed to rest in the operator's palm and a gearhousing 22.

An actuating member 24 is part of the moving device. When actuatingmember 24, which is swivellably mounted, is moved towards grip 20, arack 26 shifts in distal direction and rotates gears 28. The directionof the rotational axis is changed by 90° by means of a pinion 29 at theproximal end of a bearing 30, which supports the proximal end of theforce transmitter 8 of the moving device. The force transmitter 8comprises a rotary rod (see below), the proximal end of which is fixedto pinion 29. Thus, upon pressing the actuating member 24, the rotaryrod of the force transmitter 8 is caused to a rotary movement about alongitudinal axis. Because of the gear ratio provided by gears 28 andpinion 29, this rotational movement is relatively fast.

In a similar way, upon pressing a swivellably mounted actuating member32 against the force of a spring 33 (“firing” the instrument), a rack 34shifts in distal direction and drives gears 36 and a pinion 37 at theproximal end of a bearing 38, which results in a relatively fastrotational movement of a rotary rod of the force transmitter 9 of thestaple driving device.

In order to release (retract) the staple driving device after thestaples have been “fired”, a release button 40 has to be pressed againstthe force exerted by a spring 41. After “firing” and before pressingrelease button 40, a catch 42 engages to a protrusion of the stapledriving device and keeps rack 34 in a distal position. Moreover, rack 26is held forward and in place by this mechanism as well, while actuatingmember 32 is pressed. Pressing release button 40 lifts the catch 42,which releases the protrusion of the staple driving device such that,via the action of spring 33, rack 34 returns to its original proximalposition.

A safety feature (not shown in detail) is a pin held by a part 44 untilpart 44 is pushed out of the way upon actuation of actuating member 24.This ensures that actuating member 32 cannot be used prior to actuatingmember 24.

FIG. 6 shows the distal end region of the force transmitters 8 of themoving device and 9 of the staple driving device, including the mostdistal holder 16 and the distal end area of endoscope 6.

Force transmitter 8 comprises a flexible rotary rod 50 which isrotatably mounted in a flexible sheath 51. In the embodiment, rotary rod50 is a single flexible structure all along. Different designs, e.g. astructure comprising flexibly linked short rigid members or a tightlywound helix, are conceivable as well. At its distal end, rotary rod 50is fixed to a connector 52 which is attached to the proximal end of adrive screw 53. In a similar way, force transmitter 9 includes a rotaryrod 54, which is guided in a sheath 55 and ends at a connector 56 fixedto a drive screw 57.

FIG. 7 displays the components driven by the screws 53 and 57, but notyet the guiding parts or rails for these components. Screw 53 fits intoa threaded hole extending into longitudinal direction inside an arm 60which supports an anvil housing 62. Similarly, screw 57 fits into athreaded hole in a pusher base 64. Thus, by rotating rotary rods 50 or54, the arm 60 and the pusher base 64, respectively, are moved inlongitudinal direction of the staple fastening assembly 2.

FIG. 8 shows additional components of the staple fastening assembly 2.Both screws 53 and 57 are guided by bores in an arcuate base 65 of thestaple fastening assembly 2. Pusher base 64 supports (via anintermediate part 67) a pusher platform 66 from which a plurality ofpusher fingers 68 extend longitudinally. Each of the pusher fingers 68supports a staple 70 such that the pointed ends of the staples 70 arealigned in distal direction. The pusher fingers 68 and the relatedstaples 70 are guided in individual slots (not shown in FIG. 8) formedin the housing of the cartridge device 10. Moreover, the intermediatepart 67 supports an arcuate knife 72 having a concave side (seen in FIG.8), a convex side opposite to the concave side and a cutting edge 73.FIG. 8 also shows a guide arm 74 of the anvil 12 which extends from theanvil housing 62 and runs in parallel to arm 60.

FIG. 9 provides a better impression of the arrangement of the staples 70(which are not shown in FIG. 9 but indicated by the locations of thepusher fingers 68) and the knife 72.

The cartridge device 10 comprises three curved open rows of staples,i.e. two rows 76 and 77 on the convex side of knife 72 and one row 78 onthe concave side of knife 72.

A staple forming face 80, which is mounted on the anvil housing 62 (seeFIG. 8), is shown in FIG. 10. The staple forming face 80 is preferablymade of metal and comprises three rows of staple forming depression 82,which are aligned to the pointed ends of staples 70. Moreover, FIG. 10displays a knife depression 84, which is aligned to the cutting edge 73of knife 72 and preferably filled with a plastics material which acts ascutting block but can be cut by the knife 72.

Fixed to the staple forming face 80, there are two guide rails 86 and 87which have a lateral slot each for precisely guiding the knife 72, evenwhen it is very close to the staple forming face 80, as illustrated inFIG. 10. When the anvil 12 is moved with respect to the cartridge device10 by means of the moving device, the guide rails 86 and 87 move inlongitudinal direction as well and slide through holes 88 and 89 (seeFIG. 9) provided in the intermediate part 67 and the pusher platform 66.This movement does not affect the position of the knife 72, becauseknife 72 is fixed to the intermediate part 67.

FIG. 11 is a view similar to FIG. 8, but the cartridge device 10 hasbeen completed by a housing 90. In the embodiment, the housing 90 is aninjection-molded part made of medical grade plastics material.

FIG. 11 illustrates the state in which the anvil 12 has been moved to aspaced position, i.e. to a position in which the distance between thecartridge device 10 and the staple forming face 80 of the anvil 12 islarge. This corresponds to a large exposed area of drive screw 53 inFIG. 8.

In this spaced position, tissue of a patient to be excised can be pulledbetween the staple forming face 80 of anvil 12 and the cartridge device10. Thereafter, actuating member 24 of the moving device is pressedtowards grip 20, which causes a rotational movement of rotary rod 50 anddrive screw 53, resulting in a shift of the anvil 12 in proximaldirection. In this way, the anvil 12 reaches a closed position and thetissue is clamped.

The next step of the procedure is shown in FIG. 12 (in which the housing90 is removed). As explained, the anvil 12 has been moved to a closedposition, which is evident from a small exposed area of drive screw 53.Moreover, actuating member 32 has been pressed, which results in arotational movement of screw 57 and a longitudinal movement in distaldirection of the pusher base 64, the intermediate part 67, the pusherplatform 66, the pusher fingers 68, the staples 70 and the knife 72,wherein the cutting edge 73 of knife 72 follows the pointed ends of thestaples 70. FIG. 12 shows the state when the staples 70 have been formedby staple forming face 80. FIG. 13 displays the same state.

FIG. 14 shows a complete view of the cartridge device 10, the anvil 12and the distal end region of endoscope 6 in the same state. After thetissue has been stapled, it is cut and excised by the knife 72. In thisway, the tissue to stay with the patient is safely stapled by the rows76 and 77 of staples on the convex side of knife 72, which immediatelystops bleeding, whereas the part of the tissue to be removed from thepatient is stapled and held together by the staples of row 78. Afterstapling, release button 40 is pressed, such that rack 34 and actuatingmember 32, by means of the force exerted by spring 33, return to theiroriginal positions. Additionally, this effects a reverse motion of themoving device, increasing the distance between the anvil 12 and thecartridge device 10 in order to release the clamped tissue and to beable to remove the stapling instrument 1 from the patient. The excisedportion of the tissue remains in the staple fastening assembly 2.

FIG. 15 illustrates the components of the staple fastening assembly 2 ofthe embodiment described so far in an exploded view. Screws 92 and 93are used to attach the arcuate base 65 to part of the housing 90 ofcartridge device 10.

FIGS. 16 and 17 display a second embodiment of the surgical staplinginstrument, i.e. the stapling instrument 100. Its staple fasteningassembly 102 and its handle 104 have a similar design as the staplefastening assembly 2 and the handle 4 of the first embodiment. Incontrast thereto, however, the force transmitters are not exposed at theouter periphery of endoscope 106, but are accommodated in a flexibleguide 108. The endoscope 106 and the flexible guide 108 form theflexible backbone of stapling instrument 100.

In the embodiment, the flexible guide 108 is made of plastics materialand comprises two longitudinal channels for guiding rotary rods of theforce transmitters of the moving device and of the staple drivingdevice. An open channel 109 longitudinally extends alongside flexibleguide 108. The endoscope 106 can rest within open channel 109, as shownin FIGS. 16 and 17.

The function and use of the stapling instrument 100 are the same asthose of stapling instrument 1.

1. Surgical stapling instrument comprising: a staple fastening assembly (2; 102) in the distal end region of the instrument (1; 100), including a curved cartridge device (10), which comprises at least one curved open row (76, 77, 78) of staples (70) having a concave side and a convex side, and, opposite to the cartridge device (10), a curved anvil (12), which has a staple forming face (80) and is adapted to cooperate with the cartridge device (10) for forming the ends of the staples (70) exiting from the cartridge device (10), a moving device (8, 24, 26, 28, 29, 30, 53, 60) adapted to move the anvil (12) relatively with respect to the cartridge device (10), essentially in parallel relationship, from a spaced position for positioning tissue therebetween to a closed position for clamping the tissue, a staple driving device (9, 32, 34, 36, 37, 38, 57, 64) adapted to drive the staples (70) out of the cartridge device (10) towards the anvil (12), a handle (4; 104) in the proximal end region of the instrument (1; 100), which handle (4; 104) is operatively connected to the staple fastening assembly (2; 102) and which comprises actuating members (24, 32) coupled to force transmitters (8, 9) of the moving device and of the staple driving device, characterized in that a flexible backbone (6; 106, 108) is arranged between the handle (4; 104) and the staple fastening assembly (2; 102), which flexible backbone (6; 106, 108) guides the force transmitters (8, 9) of the moving device and of the staple driving device.
 2. Stapling instrument according to claim 1, characterized by a knife (72), which is contained in the cartridge device (10) and which is positioned on the concave side of at least one row (76, 77) of staples (70), and a knife actuating device (9, 32, 34, 36, 37, 38, 57, 64) adapted to move the knife (72) towards the anvil (12), which knife actuating device preferably is coupled to the staple driving device.
 3. Stapling instrument according to claim 1 or 2, characterized in that the flexible backbone (6; 106, 108) comprises a flexible endoscope (6; 106), which preferably is removably mounted.
 4. Stapling instrument according to claim 1 or 2, characterized in that the stapling instrument (1; 100) is adapted to be used with an independent flexible endoscope (6; 106) forming at least part of the flexible backbone (6; 106, 108).
 5. Stapling instrument according to claim 3 or 4, characterized in that the force transmitters (8, 9) of the moving device and of the staple driving device are located at the outside of the endoscope (6) and are attached to the endoscope (6) by a plurality of spaced holders (16).
 6. Stapling instrument according to claim 3 or 4, characterized in that the flexible backbone (106, 108) comprises a flexible guide (108), which is arranged alongside the endoscope (106) and which accommodates the force transmitters of the moving device and of the staple driving device.
 7. Stapling instrument according to one of claims 1 to 6, characterized in that at least one of the force transmitters (8, 9) of the moving device and of the staple driving device comprises a flexible rotary rod (50, 54) adapted to be rotated around its longitudinal axis upon actuation of the related actuating member (24, 32) of the handle (4) and adapted to transform its rotary motion to a longitudinal motion at the staple fastening assembly (2).
 8. Stapling instrument according to claim 7, characterized in that the at least one of the force transmitters (8, 9) is adapted to be rotated via a gear transmission (26, 28, 29; 34, 36, 37) operated by the related actuating member (24, 32).
 9. Stapling instrument according to claim 7 or 8, characterized in that the at least one of the force transmitters (8, 9) is adapted to transform its rotary motion to a longitudinal motion via a screw drive (53, 57).
 10. Stapling instrument according to one of claims 1 to 9, characterized in that the staple fastening assembly (2) is adapted to allow unobstructed access towards concave inner faces of the cartridge device (10) and of the anvil (12).
 11. Stapling instrument according to one of claims 1 to 10, characterized in that the staple forming face (80) of the anvil (12) is generally planar.
 12. Stapling instrument according to one of claims 1 to 11, characterized in that the cartridge device (10) and the anvil (12) have a generally arc-like shape in a cross-sectional plane, the arc extending over an angle in the range 10° to 350°.
 13. Stapling instrument according to one of claims 1 to 12, characterized in that the anvil (12) is supported by means of at least one arm (60, 74) extending from an end of the anvil (12) and generally running in parallel to the direction of relative movement of the anvil (12) with respect to the cartridge device (10).
 14. Stapling instrument according to one of claims 1 to 13, characterized in that the distance between the cartridge device (10) and the anvil (12) in the closed position is adjustable.
 15. Stapling instrument according to one of claims 1 to 14, characterized in that the cartridge device comprises a replaceable cartridge containing the staples.
 16. Stapling instrument according to one of claims 1 to 15, characterized in that the staple fastening assembly is removably mounted.
 17. Stapling instrument according to one of claims 1 to 16, characterized in that the handle is removably mounted. 